Device for collection of debris

ABSTRACT

A device ( 300 ) for collecting debris from a surface. The device has a generally planar matting material ( 15 ) the undersurface of which is formed with depending bristles ( 14 ). The device ( 300 ) has an opening ( 16 ) therethrough which when the device is moved over a ground surface ( 18 ) with the bristles ( 14 ) in contact therewith debris on the ground surface ( 18 ) pass through the opening ( 16 ). The forward and aft edges ( 361, 362 ) of the matting ( 15 ) are provided with transverse stiffening members ( 363 ). A plurality of wheels ( 365 ) at least partially support the stiffening members ( 361, 362 ).

FIELD OF THE INVENTION

This invention relates to a device for collection of debris.

BACKGROUND ART

U.S. Pat. No. 5,284,211 discloses a ground surface debris collectiondevice suitable, for example, for collecting small debris such as leavesfrom a ground surface. This comprises a device of flexible grid likeconstruction having slots so that, as the device is moved over theground surface, debris passes through the slots and onto the uppersurface of the device.

While the arrangement shown in Pat. No. 5,284,211 has been found to bevery satisfactory in use, particularly for grooming and cleaning tenniscourt surfaces, it has now been found it is not efficient as isdesirable on rougher surfaces such as rough asphalt.

International Patent Application WO96/09440 discloses a device suitablefor efficiently collecting debris from a variety of surfaces. The devicehas a generally planar matting the undersurface of which is formed withdepending bristles. An opening is provided whereby when the device ismoved across a ground surface with the bristles in contact therewith,debris on the ground surface are passed through the opening to rest onthe matting.

The device described in International Patent Application WO96/09440 hasbeen found to be particularly useful. It would be desirable to improveits operating characteristics and extend the life of the planar matting.

DISCLOSURE OF THE INVENTION

In one aspect, the invention provides a device for collecting debrisfrom a surface, comprising a generally planar member having at least aportion thereof defining an undersurface of the device formed of aconformable material such that when the device is moved over a groundsurface with the undersurface in contact with the ground surface theundersurface is caused to locally conform to undulations in the groundsurface, the device having an opening, whereby, under said movement overa ground surface, debris on the ground surface passes through theopening onto an upper surface of the device wherein said generallyplanar member has forward and aft edges corresponding to the directionthe device is moved over the ground surface, said edges being providedwith stiffening members extending transversely to the direction thedevice is moved over the ground surface and said stiffening membersbeing at least partially supported by a plurality of wheels disposed forcontact with the ground surface. The opening may be formed in oradjacent the conformable material.

The aforementioned portion may be formed from a flexible layer, such asof foam plastics material, or an open mat of sinuous fibres, such asopen looped fibres. In a preferred form, however, the conformablematerial comprises a brush-like structure. The planar member may includea backing portion which may be flexible or may be relatively rigid.

Preferably, the stiffening members are transversely extending aluminiumbars secured to the conformable material. In some applications plasticsstiffening members can be used.

The stiffening members may be stitched, glued or otherwise securelyfixed to the conformable material. In one preferred form the edge of theconformable material is formed into a hem through which the stiffeningmember extends.

In another aspect, the invention provides a device for collecting debrisfrom a surface, comprising a generally planar member having at least aportion thereof defining an undersurface of the device formed withdepending bristles thereover and the device having an openingtherethrough whereby when the device is moved over a ground surface withthe bristles in contact therewith debris on the ground surface is passedthrough the opening to an upper surface of the device wherein saidgenerally planar member has forward and aft edges corresponding to thedirection the device is moved over the ground surface, said edges beingprovided with stiffening members extending transversely to the directionthe device is moved over the ground surface and said stiffening membersbeing at least partially supported by a plurality of wheels disposed forcontact with the ground surface.

The opening may have at a rear edge thereof a forwardly and downwardlydepending surface to facilitate pick up of debris. Also, to assist inretention of debris on the device, the device may be fitted at its uppersurface with upstanding projections ridges or the like. For example, anupstanding wall may be formed along the front edge of the opening and/orat one or both side edges of the opening.

There may be a single opening, but it is preferred that there are anumber of openings.

In a still further aspect, the invention provides a device forcollecting debris from a surface, comprising a generally planar memberhaving an opening through the generally planar member whereby, undersaid movement over a ground surface, debris on the ground surface passesthrough the opening onto an upper surface of the device, the devicehaving means for entrapping debris having passed through the openingwherein said generally planar member has forward and aft edgescorresponding to the direction the device is moved over the groundsurface, said edges being provided with stiffening members extendingtransversely to the direction the device is moved over the groundsurface and said stiffening members being at least partially supportedby a plurality of wheels disposed for contact with the ground surface.The entrapping means may comprise a mesh material. The material formingthe entrapping means may comprise material which forms a cavity over theupper surface of the generally planar member. Otherwise, the device mayfor example be constructed as above described. Alternatively, it may befor example be constructed in accordance with the teachings of theabovementioned U.S. Pat. No. 5,284,211, the disclosures of which arehereby incorporated to form part of the present specification.

In each aspect of the invention the wheels are preferably spaced alongthe stiffening members. Preferably, the wheels are disposed forward andaft of at least one of the stiffening members. In one form of theinvention at least some of the wheels are arranged in pairs with onewheel of the pair forward and the other aft of the stiffening member andaligned in the direction the device is moved. The wheels preferablyprotrude through the planar member to contact the ground surface. In thecurrently preferred embodiment of the invention the stiffening memberhas wheels disposed only on the aft side. The wheels preferably have adiameter not substantially greater than the thickness of the planarmaterial.

The invention is further described by way of example only with referenceto the companying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

In the accompanying drawings:

FIG. 1 is a plan view of device constructed in accordance with theinvention;

FIG. 2 is an enlarged cross-section on the line 2—2 in FIG. 1;

FIG. 3 is an enlarged perspective view of a reinforcing frameincorporated into the device of FIG. 1;

FIGS. 4 and 5 are plan views of two further embodiments of theinvention;

FIG. 6 is a perspective view of another embodiment of the invention;

FIG. 7 is a side to side cross-section of the embodiment of FIG. 6;

FIG. 7a is an enlarged view of part of the cross-section shown in FIG.7;

FIG. 8 is a plan view of a further embodiment of the invention;

FIG. 9 is a front view of the embodiment of FIG. 8;

FIG. 10 is an end view of the embodiment of FIG. 8;

FIGS. 11 and 12 are respective cross sections on the lines 11—11 and12—12 in FIG. 8;

FIG. 13 is a plan view of a further embodiment of the invention;

FIG. 14 is a front view of the embodiment of FIG. 13;

FIG. 15 is an end view of the embodiment of FIG. 13; and

FIG. 16 is a cross section on the line 16—16 in FIG. 13.

BEST MODES FOR CARRYING OUT THE INVENTION

Referring firstly to FIGS. 1, 2 and 3, the device 10 shown therein isformed of a conformable matting material 15 having, as shown in FIG. 2,a flexible laminar base portion 12 with depending bristles 14. It hasbeen found convenient to form the device from inverted artificial grassmaterial of the kind used for the surfaces of tennis courts and thelike, arranged with the bristles extending downwardly. Generally, thematerial 15 should be flexible.

The matting material 15 has a series of rectangular sidewardly elongateopenings 16, arranged in traverse extending spaced rows. When the device10 is moved over a ground surface 18 (FIG. 2), such as by towing by useof the rope 22 (FIG. 1) at a forward end thereof, the bristles 14agitate leaves, stones and the like on the ground surface by contacttherewith and this debris tends to pass from the underside of the device10 through the openings 16 to rest on upper portions of the device 10and on the base portion 12, between the openings 16. The debris soresting on the upper side of the device 10 can be then convenientlytaken away on the device for disposal as desired. The bristles act to“flick” material into the openings 16.

In the particular form shown in FIGS. 2 and 3, each opening 16 issurrounded by a reinforcing frame 30. The frame has a peripheral edgeportion 32 which at front and side portions of the opening 16 is formedwith an upstanding wall 34. At the rear edge, the frame is formed with adownwardly angled edge pickup portion 36 which extends from a locationat the upper side of the matting material 15 forwardly and downwardly toterminate at a location which in use of the device 10 is only just abovethe ground surface 18. The frame is secured in position on the mattingmaterial 15 by use of bolts or other fixture elements 40, which extendthrough the frame and the matting material 15. Alternatively, the framemay be stitched to the matting material.

In device 100 of FIG. 4, the openings 16 are formed between side to sideextending strips 50 of matting material 15 with relatively narrowforward to rearwardly extending connector elements 52 interconnectingthe strips. Thus, each set of side by side aligned openings forms asubstantially continuous side to side aperture 54.

The device 200 of FIG. 5 is generally similar to that of FIG. 4, savethat the side to side extending apertures 54 are of “saw tooth”configuration. Alternate openings 16 in each side to side extendingaperture 54 are angled forwardly and rearwardly as shown.

The device 300 of FIGS. 6, 7 and 7 a has side to side extending strips350 formed from matting material 15 and interconnected by plasticsframes 330. In this case there are three strips 350 interconnected bytwo sets of the frames 330, with each set of frames comprising threesidewardly aligned frames. Each frame 330 comprises a forward generallyplanar horizontally extending portion 332 and a rear planar generallyhorizontally extending portion 334, co-planar with portion 332. Portion332, 334 are connected at ends of each frame 330 by end walls 336, 338and by an intermediate wall 340. Walls 330, 338, 340 are generallyplanar and vertically extending, and of relatively small thickness inthe side to side direction of the device 300, so that each framepresents two relatively large side by side openings 16.

The three front frames 330 in each set are in closely adjacent side byside relationship so as to provide, across the width of the device 10,six openings 16. Each portion 334 has a forwardly and downwardlyinclined pick-up portion 342 which extends downwardly to a locationadjacent to ground surface 18 (FIG. 7). This functions in a similarmanner to the downwardly angled pick-up portion 36 previously described.

At the rear of each frame portion 332, there is an upwardly extendingwall portion 354, these being arranged, for each set of frames, so as topresent a substantially continuous wall extending from side to side ofthe device 300.

Three end pieces 356 are provided in end to end abutting relationshipacross the width of the device 10 at the rear edge of the rear one ofthe three strips 350. These define an upstanding side to side extendingwall similarly configured to the walls provided by the side to side wallportions 354 associated with the two frames 330.

Forward edge 361 and aft edge 362 of matting material 15 are providedwith transversely extending aluminium stiffening members 363. Thestiffening members 363 may be affixed to the matting material 15 bystitching or gluing. Alternatively a hem may be formed at the edge ofthe material 15 by folding it back upon itself or securing the edge byglueing or stitching. In this arrangement the stiffening member isretained in the hem.

Wheel carriers 364 are fixed to the members 363 by bolts or otherfasteners. The carriers 364 adjacent forward edge 361 each mount asingle wheel 365 which depend through holes 366 to contact the groundsurface. Carriers 364 adjacent aft edge 362 mount pairs of wheels 365forward and aft of the stiffening member. These wheels are aligned inthe direction of movement of the device. The forward wheels 365 dependthrough holes 366 to contact the ground whilst aft wheels 365 aremounted to contact the ground behind aft edge 362.

In use stiffening members 363 provide sufficient transverse rigidity inthe forward and aft edges of the device to facilitate handling, inparticular, during removal of collected debris as described below. Thewheels 365 support the stiffening members to prevent excessive wear ofthe matting material adjacent the stiffening members. Only a single setof wheels 365 is generally required at the forward edge 361 because thetowing hitch, usually connected to the stiffening member, provides somesupport. In some applications however wheels forward and aft of thestiffening member may also be used at the forward edge. The wheels 365have a diameter not substantially greater than the thickness of mattingmaterial 15.

The wheels 365 have also been found to improve the longitudinalstability of the device 300. In particular the wheels 365 provide adegree of resistance to transverse movement of the device during use.That is, the wheels 365 cause the device 300 to track a towing vehicle(not shown). This has been found to improve the corneringcharacteristics of the device 300 since the tendency to slide is reducedand also to reduce any sideways movement when moving at relatively highspeed.

The device 300 incorporates a solid towing hitch 322. The hitch 322 hasa connecting ring 323 rigidly fixed to a bar 324. Bar 324 is pivotallyconnected to stiffening member 363 at 325. The pivotal connection 325preferably allows movement of bar 324 only in a horizontal plane. Inthis way the solid towing hitch 322 can be used to provide some supportfor the stiffening member 363 as described above.

Fine mesh screens 375 having some flexibility and resilience, arepositioned so as to extend from side to side of the device 300, theforward one of these extending from the upper edges of the wall portions354 associated with the three forward frames 330 in an upwardly archedconfiguration to corresponding locations at the wall portion 354associated with the rearwardly positioned frames 330. Similarly, therear screen 375 extends in upwardly arched configuration from the upperedge of the wall portions 354 of the rearwardly disposed frames 330 tothe upper edges of the end pieces 356. These screens 375 thus definesubstantially a closed spaces 377 above the forwardly positionedopenings 16 and the following strip 350 and above the rearwardlydisposed openings 16 and the following strip 350. If desired, thesespaces may be closed at the sides thereof such as by further meshmaterial. The screens have been found effective to trap within thespaces 377 debris collected during operation of the apparatus.Preferably they are arranged to be easily removable such as by use ofsuitable releasable fasteners to facilitate removal of debris, or debrismay simply be slipped sidewardly off the device 10 through open endedspaces 377. In alternative arrangements, the screens may be formed ofmaterial which is flexible and non resilient or may form substantiallyrigid cages on top of the device.

FIGS. 8 and 9 illustrate a modified frame 430 similar to the frame 430.In FIGS. 9 to 12, like reference numerals denote like components in FIG.6 and 7. Here, however, the angled pick-up portions 342 are of scallopedform, being provided with V-shaped notches 380 at forward edges tofacilitate the pickup of debris.

FIGS. 13 to 16 illustrate a still further modified frame 530. Again,this is generally similar to the frame 330 described in relation toFIGS. 6 and 7. Like reference numerals denote like components in FIGS. 6& 7 and 13 to 16 and the following description is confined todifferences as between frames of FIGS. 6 and 7 and of FIGS. 13 to 16.

In the frame 530, walls 336, 338 & 340 are removed, and replaced byjointed wall structures 532. Each wall structure 532 has a first portion534 extending forwardly from the rear wall portion 334 and generallyconfigured like the walls 338 previously described. The portions 534terminate short of the wall portion 354 and forward portion 332 but arejointed to rearwardly extending flange portions 536 of wall structures532 by means of pins 538. In this fashion, each wall portion 534 and theflange portion may rotate one relative to the other about the axes ofthe pins 538 so as to permit pivotal movement of the forward and rearparts of the frame. Thus, the strips 350 carried by these may likewisepivot about side to side axes of the device as a whole.

As shown, wall portion 354 of each frame 530 may have an upwardly andrearwardly extending portion 354 a extending from portion 332, and thewall portion 534 may have somewhat correspondingly angled edge 534 awhich has only a relatively small clearance relative to the portion 534a so as to somewhat limit the amount of permitted movement as betweenthe forward and rearwardly disposed parts of the frame 530.

The described devices have been found to be particularly satisfactoryfor cleaning debris from hard surfaces such as asphalt, concrete or thelike, as well as from grass and similar surfaces. It has also been foundsatisfactory for use in collecting small items such as nuts, bolts orthe like. With rough asphalt in particular, the collecting action isvery efficient, the bristles 14 acting to clean the ground surface,directing debris to the upper surface of the device.

In one form of the invention, it was found satisfactory to provideopenings 16 of dimensions of the order of 260 nm by 60 mn, with thedepth of the pile formed by the bristles 14 being of the order of 1 cm.The sizes may however be varied as necessary to adapt the invention toparticular uses. For example, the openings 16 may be of the order of 10to 300 mm length, measured in the front to rear direction of the deviceof the invention. At towing speeds of up to 30 Kph, a length of about 70mm may be satisfactory, with greater lengths being employed with fastertowing speed, for example 100 mm where speeds up to 100 Kph areemployed. Similarly, the depth of the pile provided by the bristles 14may be varied. Generally, the longer the bristles, the better is thewearability, but shorter bristles are generally more efficient, since itis easier to direct objects through a lesser distance from the groundsurface to the upper surface of the device. Practically, for smallobjects such as washers or the like a thickness of about 9 mm may besatisfactory. For large objects, greater depth may be employed. A choiceof overall thickness of matting material of 5 to 15 mm will providesatisfactory pick-up of a range of commonly encountered small objects.

The bristles 14 should generally be flexible, and some degree ofresilience is also desirable.

In an exemplary construction, the matting material 15 was artificialgrass material formed on a base of two thicknesses of thin wovenpolypropylene material, the bristles 14 being formed of flatpolypropylene fibres. The bristles 14 were formed from flat yarn ofweight 1332 gram per square meter. The material was sewn on the backingmaterial in loops along rows spaced apart approximately 4 mm. Arubber-like backing was then applied to the woven sheets at the sideopposite the loops, and the loops cut to form the bristles as upstandingtufts. Material with 27 loops per 10 cm in each row was found to besatisfactory, the tufts being of length about 9 mm. The resultantmat-like structure is somewhat crushable by impression of hand pressureon the bristles, but has sufficient resilient to cause reasonably quickrestoration to the original condition when pressure is removed. Thisartificial grass material is relatively flexible due to the basematerial (the woven material together with the rubber-like backing)being flexible.

The described artificial matting material presents an undersurfaceconstituted by the bristles which is readily able to conform to localvariations in ground surface as the device 10 is passed over the groundsurface, in particular being able to conform to surface undulations aswell as accommodating small obstacles, and providing an effectivesweeping action to agitate debris and cause it to move through theopenings 16. While it is preferred that the device include a flexiblebase with a conformable portion in the form of the described bristles,other constructions are possible. For example, a layer of foamedplastics material could be used. In general, the whole of the device 10should be flexible, although, particularly if a very thick underlayerconstituted by bristles, foam or other material is employed, this couldbe secured to a relatively rigid upper backing. In the described exampleof FIGS. 1 and 2, the leading edge of the device is provided with arigid strip 25 to facilitate maintenance of the device in a spread outcondition during towing over a surface.

In general, the dimension of the openings 16 in the front to reardirection of the device may be about the same or slightly greater thanthe front to rear distance separating adjacent openings 16, although theseparation of adjacent openings 16 may be considerably greater. Thedevice may be of any convenient dimensions. A length of the order of onemeter and a width of the order of two metres may be satisfactory forgeneral manual use.

Although the stiffening members with supporting wheels have only beenspecifically described in relation to the embodiment described withreference to FIGS. 6, 7 and 7 a it will be apparent that the samefeatures can readily be incorporated into the other describedembodiments.

The described construction has been advanced merely by way ofexplanation, and many modifications and variations may be made theretowithout departing from the spirit and scope of the invention.

What is claimed is:
 1. A device for collecting debris from a surface,comprising a generally planar member having at least a portion thereofdefining an undersurface of the device formed of a conformable materialsuch that when the device is moved over a ground surface with theundersurface in contact with the ground surface the undersurface iscaused to locally conform to undulations in the ground surface, thedevice having an opening, whereby, under said movement over a groundsurface, debris on the ground surface passes through the opening onto anupper surface of the device wherein said generally planar member hasforward and aft edges corresponding to the direction the device is movedover the ground surface, said edges being provided with stiffeningmembers extending transversely to the direction the device is moved overthe ground surface and said stiffening members being at least partiallysupported by a plurality of wheels disposed for contact with the groundsurface.
 2. A device as claimed in claim 1 wherein said wheels arespaced along said stiffening members.
 3. A device as claimed in claim 1or claim 2 wherein said wheels are disposed both forward and aft of atleast one of said stiffening members.
 4. A device as claimed in claim 3wherein at least some of said wheels are arranged in pairs, one wheel ofsaid pair being disposed respectively forward and aft of said stiffeningmember and being aligned in said direction the device is moved.
 5. Adevice as claimed in claim 1 wherein at lease some of said wheelsprotrude through said planar member.
 6. A device as claimed in claim 1wherein the stiffening member at said forward edge has said wheelsdisposed only on the aft side.
 7. A device as claimed in claim 1 whereinsaid wheels have a diameter not substantially greater than the thicknessof said planar member.
 8. A device as claimed in claim 1 wherein saidportion is formed from a flexible layer.
 9. A device as claimed in claim1 wherein said portion is formed from foam plastics material.
 10. Adevice as claimed in claim 1 wherein said portion is formed from an openmat of sinuous fibres.
 11. A device as claimed in claim 1 wherein saidconformable material comprises a brush-like structure.
 12. A device asclaimed in claim 1 wherein said conformable material comprisesartificial grass formed from a flexible backing portion with flexibledepending plastics filaments.
 13. A device as claimed in claim 1 havingentrapping means for entrapping debris passing through said opening. 14.A device as claimed in claim 1 wherein said opening is substantiallysurrounded by an open frame to which the conformable material isaffixed.
 15. A device as claimed in 14 wherein said frame is articulatedso as to enable parts of the device forward and to the rear of theopening to pivot about a side to side axis.
 16. A device as claimed inclaim 1 having a downwardly and forwardly angled pick up portion at therear edge of the opening.
 17. A device as claimed in claim 16 whereinsaid pick up portion has a scalloped front edge.
 18. A device as claimedin claim 1 wherein the opening extends through the conformable material.19. A device as claimed in claim 1 wherein the opening is adjacent anedge of the conformable material.
 20. A device as claimed in claim 1wherein there are a plurality of said openings.
 21. A device as claimedin claim 18 wherein said openings extend from side to side of thedevice.
 22. A device for collecting debris from a surface, comprising agenerally planar member having at least a portion thereof defining anundersurface of the device formed with depending bristles thereover andthe device having an opening therethrough whereby when the device ismoved over a ground surface with the bristles in contact therewithdebris on the ground surface is passed through the opening to an uppersurface of the device wherein said generally planar member has forwardand aft edges corresponding to the direction the device is moved overthe ground surface, said edges being provided with stiffening membersextending transversely to the direction the device is moved over theground surface and said stiffening members being at least partiallysupported by a plurality of wheels disposed for contact with the groundsurface.
 23. A device as claimed in claim 22 wherein said wheels arespaced along said stiffening members.
 24. A device as claimed in claim22 or claim 23 wherein said wheels are disposed both forward and aft ofat least one of said stiffening members.
 25. A device as claimed inclaim 24 wherein at least some of said wheels are arranged in pairs, onewheel of said pair being disposed respectively forward and aft of saidstiffening member and being aligned in said direction the device ismoved.
 26. A device as claimed in claim 22 wherein at least some of saidwheels protrude through said planar member.
 27. A device as claimed inclaim 22 wherein the stiffening member at said forward edge has saidwheels disposed only on the aft side.
 28. A device as claimed in claim22 wherein said wheels have a diameter not substantially greater thanthe thickness of said planar member.
 29. A device as claimed in claim 22wherein said opening has at a rear edge thereof a forwardly anddownwardly depending surface to facilitate pick up of debris.
 30. Adevice as claimed in claim 29 wherein the device is fitted at its uppersurface with upstanding projections or ridges.
 31. A device as claimedin claim 30 wherein an upstanding wall is formed along a front edge ofthe opening.
 32. A device as claimed in claim 22 wherein there are anumber of openings.
 33. A device for collecting debris from a surface,comprising a generally planar member having an opening through thegenerally planar member whereby, under said movement over a groundsurface, debris on the ground surface passes through the opening onto anupper surface of the device, the device having means for entrappingdebris having passed through the opening wherein said generally planarmember has forward and aft edges corresponding to the direction thedevice is moved over the ground surface, said edges being provided withstiffening members extending transversely to the direction the device ismoved over the ground surface and said members being at least partiallysupported by a plurality of wheels disposed for contact with the groundsurface.
 34. A device as claimed in claim 33 wherein said wheels arespaced along said stiffening members.
 35. A device as claimed in claim33 or claim 34 wherein said wheels are disposed both forward and aft ofat least one of said stiffening members.
 36. A device as claimed inclaim 35 wherein at least some of said wheels are arranged in pairs, onewheel of said pair being disposed respectively forward and aft of saidstiffening member and being aligned in said direction the device ismoved.
 37. A device as claimed in claim 33 wherein at least some of saidwheels protrude through said planar member.
 38. A device as claimed inclaim 33 wherein the stiffening member at said forward edge has saidwheels disposed only on the aft side.
 39. A device as claimed in claim33 wherein said wheels have a diameter not substantially greater thanthe thickness of said planar member.
 40. A device as claimed in claim 34wherein the entrapping means comprises a mesh material.
 41. A device asclaimed in claim 40 wherein the material forming the entrapping meanscomprises material which forms a cavity over the upper surface of thegenerally planar member.